Monday, October 12, 2009

Qiaowanlong: New Asian Brachiosaurid

Abstract: A new genus and species of brachiosaurid sauropods, Qiaowanlong kangxii gen. et sp. nov., is reported, representing the first well-preserved Early Cretaceous brachiosaurid in Asia and expanding the distribution of brachiosaurids undoubtedly into the Asian continent.

The new taxon was recovered from the late Early Cretaceous Xinminpu Group of Yujingzi Basin in northwestern Gansu Province, China, and is represented by a series of eight mid-cervical vertebrae, a right pelvic girdle and some unidentified bones.

The existence of deeply excavated cervical neural spines and a rising transition in the neural spine height among mid-cervical vertebrae clearly show the affinity of Qiaowanlong as a member of brachiosaurids.

Among brachiosaurids, Qiaowanlong shares a derived feature with the North American Early Cretaceous brachiosaurid Sauroposeidon: the lack of cranial centrodiapophyseal lamina. However, Qiaowanlong is unique in possessing a suite of features, such as a low central length/cotyle height ratio, bifurcated cervical neural spines and a much reduced ischium.

The discovery of Qiaowanlong and other new material indicates a diverse and abundant sauropod assemblage in China during the Early Cretaceous.